Field
The present disclosure relates in general to nuclear reactor scram control systems and in particular to systems and methods for enabling verification of an energization state of a solenoid included in a scram solenoid pilot valve used to initiate a scram of a nuclear reactor control rod.
Description of Related Art
Nuclear reactors included in one or more nuclear plants may include one or more sets of control rods configured to be inserted or removed from a reactor core to control the rate of nuclear reactions occurring in the reactor core. A nuclear plant may be configured to rapidly insert some or all of the control rods into a reactor core. Inserting a control rod into a reactor core may result in a rapid shutdown of the reactor core. Such a shutdown operation may be referred to as a scram, SCRAM, etc. of the nuclear reactor. A rapid insertion of a control rod into a nuclear reactor core as part of a scram of the nuclear reactor may be referred to herein as a scram of the control rod, scramming the control rod, etc.
A nuclear reactor may include equipment configured to rapidly insert one or more control rods into a nuclear reactor as part of a scram of the nuclear reactor. In some cases, a nuclear reactor includes one or more hydraulic control units (HCUs) configured to cause one or more control rods to be scrammed into a nuclear reactor as part of a scram of the nuclear reactor.
In some cases, a scram of at least one control rod is controlled by a particular solenoid valve apparatus. The solenoid valve apparatus actuates to cause the HCU to scram one or more control rods. The apparatus may include a scram solenoid pilot valve (“SSPV”). An SSPV may be configured to cause one or more corresponding HCUs to scram at least one control rod based on actuation of the SSPV. The SSPV may actuate to cause a working fluid to be introduced into the HCU. The working fluid may cause the HCU to scram at least one control rod via hydraulic force.
In some cases, an SSPV actuates based on an energization state of at least one solenoid coil (“SSPV solenoid”) included in the SSPV. An SSPV may be configured to actuate in response to at least one SSPV solenoid included therein being de-energized. As a result, a scram of at least one control rod may be implemented based on a loss of electrical power to the SSPV solenoid, thereby providing fail-safe scram functionality.